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Glaucoma is second leading cause of blindness globally
Abstract
The urgent need for more public health action to tackle glaucoma is underscored by the work of Swiss ophthalmologist Andre Mermoud, known as the 'glaucoma pope'. His charity Vision for All provides free eye health care for poor patients in India, where it has built and operates an eye hospital, and in central Africa. Glaucoma is becoming an increasingly important cause of blindness, as the world's population ages. New statistics gathered by WHO in 2002, and published in this edition of the Bulletin (Resnikoff et al., p. 844-851), show that glaucoma is now the second leading cause of blindness globally, after cataracts. Glaucoma, however, presents perhaps an even greater public health challenge than cataracts: because the blindness it causes is irreversible. WHO officials are looking into ways to address the problems caused by glaucoma which was until now estimated to be the third leading cause of blindness. "It is a major problem, we've been concerned about this for some time and we are now working hard to address this important cause of blindness," said Dr Robert Beaglehole, WHO's Director of Chronic Diseases and Health Promotion in Geneva. "It highlights the growing problem created by chronic eye diseases, including diabetic retinopathy and age-related macular degeneration," Beaglehole said. The urgent need for action is underscored by the philanthropic work of Swiss charity Vision For All. Andre Mermoud, the group's director, is the Head of the Glaucoma Unit at the Jules Gonin Eye Hospital at the University of Lausanne in Switzerland has become known as the 'glaucoma pope' for his work on the disease. Mermoud told the Bulletin that governments and public health officials face "a really big task" to improve treatment for glaucoma. "Something has to be done," Mermoud added. "Especially in Africa, it will be essential to train hundreds of eye doctors." Glaucoma is the general term for a group of similar diseases. In primary open angle glaucoma, the channels that drain fluid within the eye become blocked, causing the pressure within the eye to rise. It causes gradual loss of vision. There are few symptoms so that people may not notice for a long time that they are losing their sight. In angle closure glaucoma, there is a similar build up of fluid within the eye, but the onset is much more sudden. Symptoms include headaches, blurred vision and pain in the eye. People of Asian descent are much more likely to suffer from angle closure glaucoma, while those of African or European origin are more likely to develop primary open angle glaucoma. In Southern India, studies have shown a prevalence of glaucoma of 2.6% and 90% of these cases have never been diagnosed before, compared to about 50% previously undiagnosed when similar studies are done in Europe. In African populations, the prevalence is 1-2%, but can rise to about 10% in the Caribbean. There are several other types of glaucoma, which are less common. The paper by Resnikoff et al. reports that about 37 million people worldwide in 2002 were blind. More than 82% of all blind people are 50 years and older. There are several reasons why glaucoma has now become the second leading cause of blindness, experts say. One is age. As a population grows older, the prevalence of glaucoma rises. Another reason is the reduced importance of trachoma as a cause of blindness. …
... Glaucoma is the leading cause of irreversible blindness in the world and represents a significant public health issue. [1][2][3] Many risk factors for developing glaucoma have been described in literature: family history, elevated intraocular pressure (IOP), older age, black race, vascular diseases including hypertension (HTN), type 2 diabetes (DM2), migraine, and obstructive sleep apnea (OSA). [4][5][6][7] Primary open-angle glaucoma (POAG) is the most common type of glaucoma, accounting for 80% to 90% of all glaucoma. ...
... Each model included the predictor variables: age, gender, race/ethnicity, BMI, history of migraine, and history of OSA. In addition to these predictor variables, each regression model had one of the following predictor variables: age at HTN diagnosis for individuals with or without DM2 (model 1), age at HTN diagnosis for individuals with DM2 (model 2), age at DM2 diagnosis for individuals with or without HTN (model 3), and age at DM2 diagnosis for individuals with HTN (model 4). ...
... Glaucoma poses a significant public health concern despite a greater understanding of the potential risk factors over the last few decades. 2,3 In order to reduce disease burden, general practitioners require a better understanding of when to refer patients to ophthalmologists for screening before disease develops and when to anticipate disease in patient subgroups. In this study, we further elaborated on the relationship between several well-understood risk factors while also looking further at the role these risk factors may play in the age individuals develop POAG. ...
Jeffrey Wooliscroft,1 Rubeel Akram,1 Hafsa Zuberi,1 Betty Tong,1 Jane Gu,1 Aaron Hurd,1 Karanjit Kooner1,2 1Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA; 2Department of Ophthalmology, Veteran Affairs North Texas Health Care System Medical Center, Dallas, TX, USACorrespondence: Karanjit Kooner, Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA, Tel +1 (214) 648-4733, Fax +1 (214) 648-2270, Email Karanjit.Kooner@utsouthwestern.eduPurpose/Relevance: To determine the influence of hypertension (HTN), type 2 diabetes (DM2), migraine, and obstructive sleep apnea (OSA) on the onset of primary open-angle glaucoma (POAG) to enhance predictive accuracy.Methods: In this cross-sectional study, data for 389 eligible patients with POAG were collected through medical records review and phone surveys. All data were assessed collectively using stepwise multiple regression analysis to determine the relative contribution to age at POAG diagnosis. We used the following groups, based on age at diagnosis, HTN for patients with or without DM2 (model 1), HTN for patients with DM2 (model 2), DM2 for patients with or without HTN (model 3), and DM2 for patients with HTN (model 4).Results: In model 1, age at HTN diagnosis was associated with age at POAG diagnosis (β = 0.14; 95% CI, 0.01– 0.26, p = 0.04). In model 2, age at HTN diagnosis was not associated with age at POAG diagnosis (p > 0.05). In model 3, age at DM2 diagnosis was associated with age at POAG diagnosis (β = 0.37; 95% CI 0.16– 0.58, p = 0.001). In model 4, age at DM2 diagnosis was associated with age at POAG diagnosis (β = 0.40; 95% CI 0.00– 0.15, p = 0.003). Asian race/ethnicity was associated with early onset of POAG in model 3 (β = − 6.44; 95% CI − 12.34– 0.54, p = 0.033). OSA and migraine did not influence the onset of POAG.Conclusion: Our study found that the diagnosis of DM2 and HTN at an earlier age is associated with the early onset of POAG.Keywords: primary open-angle glaucoma, hypertension, type 2 diabetes, migraine, obstructive sleep apnea, onset of glaucoma
... This causes a gradual narrowing of the visual field and eventually blindness can occur [1,2]. Globally, glaucoma is the second leading cause of blindness and the first cause of irreversible (permanent) blindness [3][4][5]. There are several types of glaucoma: POAG (primary open-angle glaucoma with high intra-ocular pressure) is the most common form of glaucoma, which is responsible for over 90% of cases; NTG (normal tension glaucoma -primary open-angle glaucoma with normal intra-ocular pressure, particular form of open-angle glaucoma); PACG (primary closed-angle glaucoma); congenital glaucoma; and glaucoma secondary to other conditions (local trauma, adverse effects following treatments, etc.). ...
... The study included patients with glaucoma, respectively with the two nosological entities: POAG (primary open-angle glaucoma with high intraocular pressure) and NTG (primary open-angle glaucoma with normal intra-ocular pressure), diagnosed, treated, and monitored, following the objective ophthalmological examination and the ocular functional examination. Two nosological entities were identified within the POAG: POAG (IOP ≥ 21 mmHg) and NTG (IOP ≤ 20 mmHg) [3]. NTG is a progressive optic neuropathy with IOP in the normal statistical range (≤21 mmHg). ...
The purpose of the study is to assess the health of patients in the activity of tertiary prevention dedicated to preventing blindness caused by POAG (primary glaucoma with open angle and high tension) and NTG (primary glaucoma with open-angle and statistically normal tension-particular form of glaucoma with open angle) and preservation of the remaining visual function. The design of the study is epidemiological, observational, descriptive and retrospective, and uses only the data recorded in the existing records in the archives of the Ophthalmology office within the Integrated Outpatient Clinic of the Emergency Clinical Hospital of Oradea (IOCECHO) during the years 1999-2019 (anamnestic data; objective examination and paraclinical examination: intraoc-ular pressure-IOP and visual field-VF). The methods of the study included the standardized protocol: anamnesis, physical ophthalmological examination, IOP determination, and computerized perimetry with the "Fast Threshold" strategy performed with the "Opto AP-300" perimeter. The obtained results were statistically processed with a specialized software (S.P.S.S.-I.B.M. Statistics version 22). The study examined the available data of 522 patients of which 140 were men (26.8%) and 382 were women (73.2%). The gender ratio was 0.37. In the period 1999-2019, 150,844 people with ophthalmic pathology were consulted in the Ophthalmology office of IOCECHO out of which 522 patients (0.35%) were diagnosed with primitive open-angle glaucoma, 184 people (35.2%) presented high IOP (POAG), and 338 people (64.8%) had statistically normal IOP (NTG). The annual proportion of cases diagnosed with glaucoma in the total number of patients examined was between 0.1% (2005; 2008; 2010) and 2.4% in 2012, when 101 people were detected. In the studied records, no cases of uni-and/or bilateral blindness were mentioned. The mean age of glaucoma patients at the first consultation was 60.81 ± 12.14 years with high frequencies in the 55-69 age groups and at the last consultation it was 66.10 ± 12.47 years with high frequencies in the age groups between 60-74 years. Monitoring and treatment of glaucoma patients was beneficial; IOP decreased statistically significantly: in patients with POAG by 46.16%, from 30.50 ± 7.98 mmHg to 16.42 ± 3.01 mmHg (p = 0.000) and in those with NTG by 17.44%, at 16.39 ± 3.66 mmHg at 13.53 ± 1.92 mmHG (p = 0.000). The duration of treatment and monitoring was on average 5.1 ± 3.4 years, for 184 patients (35.2%) with POAG and 5.1 ± 3.8 years for 338 patients (64.8%) with NTG. Tertiary prevention of glaucoma, by providing specialized care, ensures effective control of IOP and implicitly of the long-term evolution of the disease. IOP is the only modifiable risk factor in patients with POAG and NTG and its decrease prevents the progression of the disease and emphasizes the importance of early diagnosis and treatment. The management of the glaucoma patient consisted of: complete ophthalmological examination (subjective and objective), paraclinical examination with IOP, and VF measurement Citation: Munteanu, G.Z.; Munteanu, Z.V.I.; Roiu, G.; Daina, C.M.; Moraru, R.; Moraru, L.; Trambitas, C.; Badau, D.; Daina, L.G.
... Statistically, glaucoma affects millions of people globally, with more than 64 million cases recorded in 2013, and other studies have estimated that 76 million people will be affected by 2020 and 111.5 million by 2040 [9,10]. Glaucoma is the second leading cause of blindness worldwide, preceded by cataracts [11], and it impacts 4.5 million individuals [9,12], more than 10% of the gross population [10]. Owing to the asymptotic function of glaucoma, approximately 70% of individuals with glaucoma are unaware of the illness's existence [13,14] in the early stage. ...
... Most of the previous studies concentrated on the segmentation task. As much as 17/30 papers worked on retinal landmark segmentation [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], while only 2 papers worked on disease classification [18,19], and 5 papers worked on image synthesis to address the lack of medical images [20][21][22][23][24]. However, the rest of the papers (6/30) performed multiple tasks (eg, segmentation and classification, synthesis and segmentation) [25][26][27][28][29][30]. ...
Background:
Glaucoma leads to irreversible blindness. Globally, it is the second most common retinal disease that leads to blindness, slightly less common than cataracts. Therefore, there is a great need to avoid the silent growth of this disease using recently developed generative adversarial networks (GANs).
Objective:
This paper aims to introduce generative adversarial network technology for the diagnosis of eye disorders, particularly glaucoma. This paper illustrates deep adversarial learning as a potential diagnostic tool and the challenges involved in its implementation. This study describes and analyzes many of the pitfalls and problems that researchers will need to overcome to implement this kind of technology.
Methods:
To organize this review comprehensively, articles and reviews were collected using the following keywords: ("Glaucoma", "optic disc", "blood vessels") and ("receptive field", "loss function", "GAN", "Generative Adversarial Network", "Deep learning", "CNN", "convolutional neural network" OR encoder). The records were identified from five highly reputed databases: IEEE Xplore, Web of Science, Scopus, Science Direct, and PubMed. These libraries broadly cover the technical and medical literature. Among the last five years of publications, only papers within the specified duration were included because the target GAN technique was invented in 2014 by Goodfellow and the publishing date of the collected papers was not earlier than 2016. Duplicate records were removed, and irrelevant titles and abstracts were excluded. In addition, we excluded papers that used optical coherence tomography (OCT) and visual field images, except for those with two-dimensional images. A large-scale systematic analysis was performed, and then a summarized taxonomy was generated. Furthermore, the results of the collected articles were summarized and added to multimedia appendix 1 and a visual representation of the results on a T-shaped matrix diagram. This study was conducted between March 2020 and November 2020.
Results:
We found 59 articles after conducting a comprehensive survey of the literature. Among the 59 articles, 29 present actual attempts to synthesize images and provide accurate segmentation/classification using single/multiple landmarks or share certain experiences. Twenty-nine journal articles discuss recent advances in generative adversarial networks, practical experiments, and analytical studies of retinal disease.
Conclusions:
Recent deep learning techniques, namely, generative adversarial networks, have shown encouraging retinal disease detection performance. Although this methodology involves an extensive computing budget and optimization process, it saturates the greedy nature of deep learning techniques by synthesizing images and solves major medical issues. This paper contributes to this research field by offering a thorough analysis of existing works, highlighting current limitations, and suggesting alternatives to support other researchers and participants in further improving and strengthening future work. Finally, new directions for this research have been identified.
Clinicaltrial:
... Glaucoma, the second most common cause of blindness worldwide [99], is a neurodegenerative disease that affects the optic nerve, exclusively the retinal ganglion cells (RGCs) in the neural retina and their axons in the optic nerve. As a proven source of persistent chronic inflammation, the periodontal pathogens induce vascular alterations, resulting in activation of the local immune system within the retina and optic nerve head, allowing circulating immune or bacterial components to gain access to these sites. ...
... Astafurov et al. in their pilot case-control study found that peripheral or extra-ocular bacterial activity could be potentially contributing to the pathogenesis of glaucoma [75,77] (Table 1). The oral bacterial load in patients with glaucoma was significantly higher than those without glaucoma, suggesting that glaucoma subjects are constantly exposed to higher levels of bacterial products (p < 0.017), which potentially exacerbate the severity and/or disease progression [74][75][76][77][99][100][101][102][103] (Figure 1). Moreover, low oral Lactococcus in the glaucoma population suggests that microbial dysbiosis could play an important role in glaucoma [74]. ...
Fascinatingly, the immune-privileged healthy eye has a small unique population of microbiota. The human microbiome project led to continuing interest in the ocular microbiome. Typically, ocular microflorae are commensals of low diversity that colonize the external and internal sites of the eye, without instigating any disorders. Ocular commensals modulate immunity and optimally regulate host defense against pathogenic invasion, both on the ocular surface and neuroretina. Yet, any alteration in this symbiotic relationship culminates in the perturbation of ocular homeostasis and shifts the equilibrium toward local or systemic inflammation and, in turn, impaired visual function. A compositional variation in the ocular microbiota is associated with surface disorders such as keratitis, blepharitis, and conjunctivitis. Nevertheless, innovative studies now implicate non-ocular microbial dysbiosis in glaucoma, age-related macular degeneration (AMD), uveitis, and diabetic retinopathy. Accordingly, prompt identification of the extra-ocular etiology and a methodical understanding of the mechanisms of invasion and host-microbial interaction is of paramount importance for preventative and therapeutic interventions for vision-threatening conditions. This review article aims to explore the current literature evidence to better comprehend the role of oral pathogens in the etiopathogenesis of ocular diseases, specifically AMD.
... Glaucoma, the leading cause of irreversible blindness, is a retinal neurodegenerative disease, which affects over 60 million people around the world [1][2][3]. Progressive apoptotic death of retinal ganglion cells (RGCs) and degeneration of RGC axons and dendrites, resulting in visual field loss, are the fundamental pathogenesis of glaucoma [4][5][6][7][8]. Although aging is the chief risk factor for the development of glaucoma and sensitivity of ocular tissues to elevated IOP is an associated risk factor [9,10]; however, reduction of IOP could not completely prevent the pathological progression of glaucoma [11,12], suggesting that the mechanisms underlying RGC loss in glaucoma are complicated. ...
... Recombinant rat TNF-α (5 ng in 1 ml of 0.9% saline with 0.1% BSA, R&D systems, Minneapolis, MN, USA) (2 μl) was injected into the right vitreous cavity of the anesthetized rat with a micro-injector (Hamilton, Reno, NV, USA) under a stereoscopic microscope (Carl Zeiss). Given that the vitreous volume is ∼20 μl [33,34], the concentration of TNF-α in the vitreous cavity is ∼0.5 ng/ ml. 2 μl of 8-chloro-4-(phenylthio)-1-(trifluoromethyl)- [1,2,4]triazolo [4,3-a]quinoxaline (R7050, 10 μM, Tocris Bioscience, Ellisville, USA), BAY 11-7082 (10 μM), stattic (10 μM), or SB203580 (10 μM) (Selleck Chemical, Houston, TX) was intravitreally injected in the same manner. The eyes that received saline injection were used as controls. ...
Background
Neuroinflammation plays an important role in the pathogenesis of glaucoma. Tumor necrosis factor-alpha (TNF-α) is a major pro-inflammatory cytokine released from activated retinal glial cells in glaucoma. Here, we investigated how TNF-α induces retinal ganglion cell (RGC) hyperexcitability and injury.
Methods
Whole-cell patch-clamp techniques were performed to explore changes in spontaneous firing and evoked action potentials, and Na ⁺ currents in RGCs. Both intravitreal injection of TNF-α and chronic ocular hypertension (COH) models were used. Western blotting, immunofluorescence, quantitative real-time polymerase chain reaction (q-PCR), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) techniques were employed to investigate the molecular mechanisms of TNF-α effects on RGCs.
Results
Intravitreal injection of soluble TNF-α significantly increased the spontaneous firing frequencies of RGCs in retinal slices. When the synaptic transmissions were blocked, more than 90% of RGCs still showed spontaneous firing; both the percentage of cells and firing frequency were higher than the controls. Furthermore, the frequency of evoked action potentials was also higher than the controls. Co-injection of the TNF-α receptor 1 (TNFR1) inhibitor R7050 eliminated the TNF-α-induced effects, suggesting that TNF-α may directly act on RGCs to induce cell hyperexcitability through activating TNFR1. In RGCs acutely isolated from TNF-α-injected retinas, Na ⁺ current densities were upregulated. Perfusing TNF-α in RGCs of normal rats mimicked this effect, and the activation curve of Na ⁺ currents shifted toward hyperpolarization direction, which was mediated through p38 MAPK and STAT3 signaling pathways. Further analysis revealed that TNF-α selectively upregulated Nav1.6 subtype of Na ⁺ currents in RGCs. Similar to observations in retinas of rats with COH, intravitreal injection of TNF-α upregulated the expression of Nav1.6 proteins in both total cell and membrane components, which was reversed by the NF-κB inhibitor BAY 11-7082. Inhibition of TNFR1 blocked TNF-α-induced RGC apoptosis.
Conclusions
TNF-α/TNFR1 signaling induces RGC hyperexcitability by selectively upregulating Nav1.6 Na ⁺ channels, thus contributing to RGC apoptosis in glaucoma.
... The second most common cause of blindness in the world is due to Glaucoma. It is a major cause of irreversible blindness (Resnikoff S et al., 2004;Kingman S, 2004;Quigley HA et al., 2006). The World Health Organization estimated that the prevalence of blindness from glaucoma amongst people over the age of fifty years is 3.4% in South East Asia . ...
... The World Health Organization estimated that the prevalence of blindness from glaucoma amongst people over the age of fifty years is 3.4% in South East Asia . It had been estimated that by 2010, 60.5 million people globally would be affected by primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) and 47% of those with glaucoma will be Asian (Kingman S, 2004;Quigley HA et al., 2006;Wong TY et al., 2006). By the year 2020, there will be 21 million people worldwide affected by PACG with a mean prevalence of 0.69% and 87% of them will reside in Asia. ...
Introduction: The second most common cause of blindness in the world is glaucoma. Family history plays an important role in early detection and management of patients with glaucoma. The main objective of this study was to determine the prevalence of glaucoma in first degree relatives of Primary open angle glaucoma (POAG) and Primary angle closure glaucoma (PACG) patients. Glaucoma awareness among the first degree relatives was also assessed. Materials and methods: A cross sectional hospital based study was designed to examine and diagnose glaucoma among first degree relatives of patients with POAG and PACG, attending the outpatient department at Ramlal Golchha Eye Hospital in the Eastern region of Nepal from June 2016 to May 2017. A comprehensive eye examination was conducted by a glaucoma specialist at the hospital. All subjects underwent vision screening, refraction, slit lamp biomicroscopy, intraocular pressure (IOP) measurement, gonioscopy and a dilated fundus examination. All glaucoma suspects and those diagnosed with glaucoma were enrolled for visual field examination.Results: Two hundred and twenty-seven first degree relatives of 72 patients were invited for the examination. Out of 227 individuals, 131 (males 67.94%, females 32.06%) agreed to participate in the study. A total of 23 (17.56%) individuals were diagnosed with glaucoma, 10 (43.47%) as POAG and 13 (56.52%) as PACG. Fourteen percent of parents, 22% of siblings and 9% of off-springs had open angle glaucoma. Among 13 PACG participants, 26.08% of parents, 26.08% of siblings and 4.34% of off-springs had angle closure glaucoma. Awareness among first degree relatives diagnosed with glaucoma was 21.74%. Conclusion: The prevalence of glaucoma among first degree relatives of glaucoma patients was higher than individuals without family history of glaucoma. Promoting awareness on glaucoma and the timely screening of family members can lead to early detection and prevention of blindness from the disease.
... Glaucoma consists in the main cause of irreversible blindness worldwide [1]. e disease is considered as a progressive and chronic optic neuropathy, characterized by specific changes on the optic nerve head (ONH), peripapillary retinal nerve fiber layer (pRNFL), and visual field (VF) [2,3]. ...
Purpose. To investigate structural and functional correlations in glaucoma patients using optic nerve head hemoglobin (ONH Hb) measurements as determined by automated colorimetric analysis of conventional retinography. Methods. We prospectively enrolled healthy participants and glaucomatous patients with a wide range of disease stages. All participants underwent visual field (VF) testing (standard automated perimetry, SAP), color fundus imaging (mydriatic retinography), and peripapillary retinal nerve fiber layer (pRNFL) assessment through spectral-domain optical coherence tomography (SD-OCT). Software Laguna ONhE was used to estimate the amount of ONH Hb and to determine the glaucoma discriminant function (GDF) index. Scatter plots were constructed, and regression analysis was used to investigate the correlations between GDF, average pRNFL thickness, and VF mean deviation (VFMD) index values. A secondary analysis was performed to compare each parameter between three different glaucoma groups divided according to VFMD values (mild, >−6 dB; moderate, −6 to −12 dB; and advanced, <−12 dB). Results. One hundred ninety-six eyes from 123 participants (69 with glaucoma and 54 controls) were enrolled. Overall, all parameters evaluated differed significantly between glaucomatous and control eyes (). The comparison of each parameter according to groups of disease stages revealed significant differences between controls and each of the glaucomatous groups (). More pronounced changes in GDF values were observed in early disease stages. We found significant nonlinear correlations between GDF and VFMD values (R² = 0.295, ) and between pRNFL thickness and VFMD (R² = 0.598, ). A linear correlation was found between GDF and pRNFL thickness values (R² = 0.195, ). Conclusion. Our results showed significant associations between ONH Hb values and both structural and functional damage in glaucoma obtained by SD-OCT and SAP, respectively. The nonlinear correlation we found and the GDF behavior along different disease stages suggest that ONH Hb levels’ reduction may precede visual function changes in early glaucoma stages.
1. Introduction
Glaucoma consists in the main cause of irreversible blindness worldwide [1]. The disease is considered as a progressive and chronic optic neuropathy, characterized by specific changes on the optic nerve head (ONH), peripapillary retinal nerve fiber layer (pRNFL), and visual field (VF) [2, 3]. Disease control and blindness prevention are strictly related to early diagnosis [2, 3]. However, the diagnosis of glaucoma can be challenging in the early stages of the disease, especially for general ophthalmologists [4, 5]. Taking this into account, it is essential to perform the correlation between structural and functional changes. Anatomical evaluation can be performed through stereoscopic retinography [6] and automated quantitative exams such as optical coherence tomography (OCT) which were developed with the aim of contributing to the diagnosis of the disease [7–9]. Nevertheless, the high cost can represent a limitation to the access of the referred diagnostic tools.
Considering the pathological mechanisms of glaucoma, vascular dysfunction has been related to the optic nerve glaucomatous lesion [10]. The access to these vascular changes can be achieved through some diagnostic tests. At first, one can mention the evaluation of the ocular blood flow, through nearby vessels, using echo Doppler [11]. Other tests were developed to measure oxygen concentration in the optic nerve [12], blood flow, and vascular structure with the emergence and clinical application of OCT angiography (OCT-A) [13].
Previous studies have evaluated the hypothesis of a relationship between tissue perfusion and the level of hemoglobin (Hb) and oxygenation. Tissues with adequate perfusion demonstrate a good level of Hb, whereas low levels occur in tissue loss [14, 15]. Some studies have proposed a simple method for measuring hemoglobin levels in the ONH, assessing conventional retinography through automated colorimetric analysis, using software Laguna ONhE [16–19]. These preceding data have demonstrated that lower levels of optic nerve head hemoglobin (ONH Hb) are found in patients with established glaucoma, along with high reproducibility results, both in glaucomatous and nonglaucomatous eyes [15].
All these considered, we sought to investigate the correlation between the levels of ONH Hb, assessed by automated colorimetric analysis, and the levels of structural and functional damage, obtained by spectral-domain optical coherence tomography (SD-OCT) and standard automated perimetry (SAP), respectively, in glaucomatous patients.
2. Methods
This study protocol, according to the tenets of the Declaration of Helsinki, was approved by the ethics committee and the institutional review board of the Federal University of São Paulo (CEP: 4.055.180). Written informed consent was obtained by all participants prior to enrollment and examination.
2.1. Participants
In this observational cross-sectional study, we included consecutive healthy individuals and patients with primary open-angle glaucoma attending to the Glaucoma Sector of Hospital Medicina dos Olhos (São Paulo, Brazil) between May 2020 and January 2021.
Glaucoma was defined as the presence of glaucomatous optic neuropathy (GON) associated or not with the corresponding VF alteration. The criteria used to define the disease were the same as those used by our research group in previous studies [20, 21]. GON was considered in the presence of a vertical cup-to-disc ratio (VCDR) greater than or equal to 0.6, asymmetry of VCDR between the eyes (greater than 0.2), detection of localized or diffuse pRNFL defects, or neuroretinal rim defects, without other pathologies that could explain these changes. We adopted VF glaucomatous defect in the SAP (Humphrey SITA—Standard 24-2, Carl Zeiss Meditec, Dublin, CA), if there were, on the pattern deviation plot, three or more points in clusters with a probability of less than 5% (points directly above and below the blind spot or on the edge of the field were excluded), a pattern standard deviation index with a probability of less than 5%, or the result outside the normal limits on glaucoma hemifield test.
The following exclusion criteria were adopted: age ≤18 years, previous ocular trauma or posterior segment intraocular surgery, significant media opacity, difficulty in performing the exams, diagnosis of primary angle closure or secondary glaucoma, and presence of ocular diseases other than glaucoma that could influence the results, such as diabetic or hypertensive retinopathy and macular edema.
Regarding the control group, nonglaucomatous patients were included, demonstrating normal appearance of the optic disc, such as a VCDR less than 0.6, absence of defects on the neuroretinal rim or pRNFL, and intraocular pressure (IOP) less than 21 mmHg, without treatment [20].
2.2. Study Protocol
Complete ophthalmological examination was performed in all participants. This evaluation included clinical history, best-corrected visual acuity, slit-lamp biomicroscopy, IOP measurement with Goldmann applanation tonometry, gonioscopy, ultrasound pachymetry, dilated fundus examination, VF testing (Humphrey SITA—Standard 24-2, Carl Zeiss Meditec, Dublin, CA), color fundus imaging (mydriatic fundus retinography Canon CR-2; Canon, Tokyo, Japan), and pRNFL and topographic ONH measurements based on SD-OCT (RTVue-100 OCT; Optovue Inc., Fremont, CA).
Accepted reliability indices for this protocol include patients’ experience in performing VF testing (at least 3 previous exams). Patients were excluded from the study if the exams presented >15% false positives or >33% loss of fixation or false negative. Additionally, during SAP review, the exam was eliminated in the presence of some artifacts such as edge defects, inattention or loss of fixation, fatigue effect, or alterations indicative of pathologies other than glaucoma.
The color fundus retinography was then analyzed by Laguna ONhE software. The full description of the program was presented in a previous study [16]. Summarizing, Laguna ONhE analyzes conventional fundus photographs to measure the amount of ONH Hb. Software considers three spectral components of ONH photographs: red, green, and blue. The red component is reflected by ONH areas with a high Hb content. On the contrary, a smaller proportion of the red light, compared to green and blue components, is reflected in areas with low Hb content. The analysis of various formulas, based on the reflected amounts of red, green, and blue light, was almost linearly proportional to the amount of Hb present [16]. Figure 1 demonstrates examples of patients with normal and glaucomatous papilla and the respective pseudo-images indicating the Hb levels. Finally, software determines an index of glaucoma discriminant function (GDF), based on colorimetric analysis and OHN Hb levels [16]. This index was performed by dividing the ONH into 3 concentric rings, and each one of them was divided into 8 parts, a total of 24 sectors. The sectors that showed the greatest difference in the amount of Hb, between eyes of patients with glaucoma and control, were those located in the vertical region, especially sectors 8 and 20, as shown in a previous study. From this, the GDF takes into account the slope of the Hb amount with the mean of these specific sectors (8 and 20) presenting 89% sensitivity at 95% specificity [16].
(a)
... Glaucoma is a term describing a group of ocular disorders with multi factorial etiology united by a clinically characteristic intraocular pressure associated optic neuropathy. 1 It is the second leading cause of blindness worldwide. 2 It is the most common cause of irreversible blindness worldwide. 3 It is estimated that there are approximately 11.2 million persons aged 40 years or older suffering from glaucoma in India. ...
... 8 Again, the interdependency of all these sources regarding choroidal and ocular control is not understood. 5 According to WHO reports, glaucoma is the second leading cause of blindness worldwide, 9 and high intraocular pressure (IOP) is one of the major risk factors. 10 11 This, however, cannot explain glaucoma(s) associated with normal IOP, and here dysregulation of ocular blood flow is one of the generally accepted causes. ...
Background
The choroid is densely innervated by all parts of the autonomic nervous system and further harbours a network of local nerve cells, the intrinsic choroidal neurons (ICN). Their function in ocular control is currently unknown. While morphological data assume a role in intraocular pressure regulation, we here test if increased pressure on isolated choroids may activate ICN.
Methods
Donor tissue was transferred into a pressurisable tissue culture chamber, and nasal and temporal choroid halves incubated for 1 or 4 hours, with pressures set to 15 or 50 mm Hg, followed by qRT-PCR expression analysis of the ICN-specific markers VIP, UCN, NOS1, UCH-L1. POL2-normalised data in the different pressure settings, incubation times and localisations were statistically analysed.
Results
The presence of the ICN-specific markers VIP, UCN, NOS1, UCH-L1 was confirmed using immunohistochemistry, and mRNA of all markers was detected in all experimental conditions. Marker analysis revealed no significant changes of mRNA expression levels between 15 and 50 mm Hg in the different incubation times. When comparing all samples over all experimental conditions, a significant increase of VIP and NOS1 mRNA was detected in temporal versus nasal choroids.
Conclusion
In this functional analysis of human ICN in vitro, higher amounts of VIP and NOS1 mRNA were detected in the temporal choroid, that is, the choroidal site with ICN accumulation. Further, our data indicate that elevated pressure is apparently not able to trigger ICN responses via the investigated markers. Alternative markers and stimuli need to be investigated in upcoming studies in order to unravel ICN function.
... 12,13 With demographic changes in industrialized countries, the incidence of glaucoma is increasing. 14,15 As this eye disease is one of the most common causes of blindness, 16,17 cost-effective, rapid, and precise screening is a key factor in rapid medical intervention. ...
Significance:
Light-field fundus photography has the potential to be a new milestone in ophthalmology. Up-to-date publications show only unsatisfactory image quality, preventing the use of depth measurements. We show that good image quality and, consequently, reliable depth measurements are possible, and we investigate the current challenges of this novel technology.
Aim:
We investigated whether light field (LF) imaging of the retina provides depth information, on which structures the depth is estimated, which illumination wavelength should be used, whether deeper layers are measurable, and what kinds of artifacts occur.
Approach:
The technical setup, a mydriatic fundus camera with an LF imager, and depth estimation were validated by an eye model and in vivo measurements of three healthy subjects and three subjects with suspected glaucoma. Comparisons between subjects and the corresponding optical coherence tomography (OCT) measurements were used for verification of the depth estimation.
Results:
This LF setup allowed for three-dimensional one-shot imaging and depth estimation of the optic disc with green light. In addition, a linear relationship was found between the depth estimates of the OCT and those of the setup developed here. This result is supported by the eye model study. Deeper layers were not measurable.
Conclusions:
If image artifacts can be handled, LF technology has the potential to help diagnose and monitor glaucoma risk at an early stage through a rapid, cost-effective one-shot technology.
... Primary angle-closure glaucoma (PACG) is one of the leading causes of irreversible blindness, disproportionally affecting Asians (1). It has been estimated to affect more than 20 million people worldwide by 2020 (2). ...
Objective: To evaluate the accuracy of different intraocular lens (IOL) power calculation formulas and develop prognostic nomograms to predict the risk of postoperative refractive error in primary angle-closure glaucoma (PACG) patients.
Methods: A total of 111 eyes with PACG underwent goniosynechialysis combined with phacoemulsification and IOL implantation were included. SRK/T, Barrett II, Hoffer Q, and Kane formulas were used to predict postoperative refraction. Prediction error (PE) and absolute predictive error (APE) produced by the four formulas were calculated and compared. An APE >0.50 D was defined as the event. Binary logistic regression analysis and prognostic nomogram models were conducted to investigate reliable predictors associated with postoperative refraction.
Results: The Kane (−0.06 D) and Barrett II (−0.07 D) formulas had mean prediction error close to zero ( p = 0.44, p = 0.41, respectively). The Hoffer Q and SRK/T produced significantly myopic outcomes ( p = 0.003, p = 0.013, respectively). The percentage of eyes within ± 0.5 D was 49.5% (55/111), 44.1% (49/111), 43.2% (48/111), and 49.5% (54/111), for the Kane, Barrett II, Hoffer Q, and SRK/T formula, respectively. Nomogram showed that AL had the greatest impact on the refractive outcomes, indicating a shorter preoperative AL is associated with a greater probability of refractive error event. The area under the receiver operator curve (AUC) of the nomogram for the Kane, Barrett II, Hoffer Q, and SRK/T was 0.690, 0.701, 0.708, and 0.676, respectively.
Conclusions: The Kane and Barrett II formulas were comparable, and they outperformed Hoffer Q and SRK/T in the total eyes with PACG receiving cataract surgery combined with goniosynechialysis. The developed nomogram models can effectively predict the occurrence of postoperative refractive error events.
... Glaucoma is the world's leading cause of irreversible blindness and continues to pose a major challenge for clinicians and patients alike [1,2]. Current approaches to treatment target the reduction of intraocular pressure (IOP), the only clinically-validated, modifiable risk factor associated with the disease [3]. ...
IntroductionTo investigate the effect of applying negative pressure (vacuum) to the periocular space on intraocular pressure (IOP) and retrobulbar pressure (RBP) by use of the Multi-Pressure Dial (MPD) system (Equinox Ophthalmic, Inc.).Methods
Two eyes of two full body cadavers were studied. In each subject, the retrobulbar space, posterior segment and intra-goggle space were cannulated to provide direct IOP, RBP and intra-goggle pressure measurements via a pressure transducer data acquisition system. The goggles of the MPD system were placed over the eyes of each subject, and multiple test runs were performed, with negative pressure settings programmed to 5, 10 and 20 mmHg. IOP and RBP measurements were continuously obtained during each run and plotted against time for analysis.ResultsFor both subjects, the mean reduction (± standard deviation) in IOP was 1.6 ± 0.9 (10%), 3.5 ± 1.8 (23%) and 5.6 ± 2.0 (37%) mmHg at programmed negative pressure levels of − 5, − 10 and − 20 mmHg, respectively. The overall mean change in RBP (mmHg) during negative pressure application was 0.02 ± 0.14 at − 5 mmHg, 0.03 ± 0.19 at − 10 mmHg and − 0.01 ± 0.18 at − 20 mmHg. In both subjects, the magnitude of RBP change during application of negative pressure fell below the uncertainty of the measurement system.Conclusions
The application of negative pressure to the periocular space with the MPD decreases IOP but does not affect RBP.
... Glaucoma is the leading cause of irreversible blindness worldwide, and it is estimated that by 2040 it will affect over 110 million people [1,2]. It is a group of progressive optic neuropathies, with characteristic anatomical and functional damage to the optic nerve. ...
Purpose
To characterize glaucoma-induced damage following injections of plastic microbeads into the anterior chamber of mice.
Methods
Mice were divided into three groups: a single plastic microbeads injection (n = 21); two consecutive plastic microbead injections to the right eye at 1-week intervals, 4 of which with two consecutive saline injections in the left eye (n = 15); and an additional control group of two consecutive saline injections at 1-week intervals (n = 6). Intraocular pressure (IOP) was measured weekly. Retinal thickness, ganglion cells (RGCs) and axonal loss, inflammatory and gliosis reactions were measured at week four. Molecular analysis using qRT-PCR in the microbeads injection groups focused on expression levels of inflammation and glaucoma-related genes.
Results
Mean IOP following single injection at 4 weeks was significantly elevated compared to baseline in injected eyes (14.5 ± 3.3 mmHg vs. 11.1 ± 2.5 mmHg, respectively, p = 0.003) and not in fellow eyes (13.2 ± 2.9 mmHg vs. 12.2 ± 2.9, respectively, NS). Six (35.3%) bead-injected eyes had IOP ≥ 17 mmHg compared with 2 (11.8%) saline-injected control eyes. Retinal thickness in injected and fellow eyes was 193.7 ± 15.5 µm and 223.9 ± 15.5 µm, respectively (p = 0.03). RGC loss in injected and fellow eyes was 16.0 ± 0.5 and 17.6 ± 0.7 cells per 200 µm, respectively (p = 0.005). Retinal gliosis, axonal loss and inflammatory cell infiltration to the bead-injected eyes were noted. Molecular analysis following double injection showed STAT3 expression decreased in the glaucoma-induced optic nerves (0.69 ± 0.3 vs. 1.16 ± 0.3, p = 0.04), but increased in the glaucoma-induced retinae (p = 0.05) versus saline; retinal IL-1β decreased significantly (0.04 ± 0.04 vs. 0.36 ± 0.2, p = 0.02). TNF-α, NFkB and SOD-1 expression did not change.
Conclusion
One/two injections of microbeads elevated IOP, with measurable neuronal damage. An inflammatory response was detected in the injured retina and optic nerve. The therapeutic significance of these findings should be explored.
... Glaucoma is one of the leading causes of blindness 1,2 and currently affects about 80 million people worldwide. Concurrently, the number of glaucoma patients is expected to rise toward 112 million by 2040. 3 Visual field (VF) testing is an integral part of glaucoma diagnosis and its follow-up monitoring 4 and standard automated perimetry (SAP) is the current gold standard VF testing approach. ...
Purpose:
Clinically evaluate the noninferiority of a custom virtual reality (VR) perimetry system when compared to a clinically and routinely used perimeter on both healthy subjects and glaucoma patients.
Methods:
We use a custom-designed VR perimetry system tailored for visual field testing. The system uses Oculus Quest VR headset (Facebook Technologies, LLC, Bern, Switzerland), that includes a clicker for participant response feedback. A prospective, single center, study was conducted at the Department of Ophthalmology of the Bern University Hospital (Bern, Switzerland) for 12 months. Of the 114 participants recruited 70 subjects (36 healthy and 34 glaucoma patients with early to moderate visual field loss) were included in the study. Participants underwent perimetry tests on an Octopus 900 (Haag-Streit, Köniz, Switzerland) as well as on the custom VR perimeter. In both cases, standard dynamic strategy (DS) was used in conjunction with the G testing pattern. Collected visual fields (VFs) from both devices were then analyzed and compared.
Results:
High mean defect (MD) correlations between the two systems (Spearman, ρ ≥ 0.75) were obtained. The VR system was found to slightly underestimate VF defects in glaucoma subjects (1.4 dB). No significant bias was found with respect to eccentricity or subject age. On average, a similar number of stimuli presentations per VF was necessary when measuring glaucoma patients and healthy subjects.
Conclusions:
This study demonstrates that a clinically used perimeter and the proposed VR perimetry system have comparable performances with respect to a number of perimetry parameters in healthy and glaucoma patients with early to moderate visual field loss.
Translational relevance:
This suggests that VR perimeters have the potential to assess VFs with high enough confidence, whereby alleviating challenges in current perimetry practices by providing a portable and more accessible visual field test.
... Glaucoma is a leading cause of irreversible blindness worldwide. [1,2] Elevated intraocular pressure (IOP) is one of the major risk factors for development and progression of open angle glaucoma (OAG) and its reduction is considered the only intervention proved to slow progression of the disease. [3] IOP reduction is currently achieved by topical hypotensive medications, laser therapy, or incisional surgical procedures. ...
Purpose:
To compare the outcomes of iStent vs. iStent inject implantation combined with phacoemulsification.
Methods:
This single center retrospective comparative case series included subjects with open angle glaucoma who underwent iStent or iStent inject implantation combined with phacoemulsification with ≥1 year follow-up. The main outcome measures were in-group and between-group changes in intraocular pressure (IOP) and medication number, proportion of eyes that achieved IOP ≤15 mmHg, and surgical success defined as 20% IOP reduction from baseline at 6/12 months. Univariate/multivariate regression analyses were done to identify predictors of surgical failure.
Results:
One hundred ninety-seven eyes of 148 patients were included (122 iStent, 75 iStent inject). Both groups achieved significant IOP and medication reduction at months 6/12 (P < 0.05). At month 6, IOP was significantly lower in iStent inject vs. iStent eyes (P = 0.003), but the difference was insignificant by month 12 (P = 0.172). Medication number was comparable in both groups at months 6/12 (P > 0.05). More iStent inject eyes achieved IOP ≤15 mmHg at month 6 (P = 0.003) and 12 (P = 0.047). Surgical success was comparable in both groups at months 6/12 (P > 0.05). Kaplan–Meier survival analysis showed similar cumulative rate of surgical failure at year-1 in both groups (P = 0.644). The multivariate model identified older age (P = 0.017) and lower baseline IOP (P = 0.002) as the strongest predictors of surgical failure.
Conclusion:
Compared to iStent, iStent inject achieved lower IOP at month 6 and higher proportion of eyes achieved IOP ≤15 mmHg at month 6/12. However, surgical success was similar in both groups. Predictors of surgical failure were older age and lower baseline IOP rather than the stent type.
... Primary glaucoma is the leading cause of irreversible visual field (VF) defect and blindness (Kingman, 2004). There were an estimated 79.6 million patients with glaucoma worldwide in 2020 , and this number is expected to rise to 111.8 million by 2040 (Tham et al., 2014), with a disproportionate impact on people in Asia and Africa. ...
Purpose: We evaluated the level of sex hormones in female patients with primary open angle glaucoma (POAG) to determine whether they are associated with the onset and/or progression of POAG.
Methods: The cross-sectional study enrolled 63 women with POAG and 56 healthy women as normal control subjects. Furthermore, 57 women with POAG were included and followed-up for at least 2 years in the cohort study. All subjects were evaluated for serum concentration of sex hormones [prolactin (PRL), luteinizing hormone (LH), testosterone (TESTO), follicle-stimulating hormone (FSH), progesterone (PROG), and estrogen (E2)] and underwent visual field (VF) examination. In the cross-sectional study, Spearman analysis, linear regression analysis, and logistic regression analysis were performed to assess risk factors for POAG in women. In the cohort study, Cox regression analyses and Kaplan–Meier survival analysis were performed to identify factors associated with VF progression in women with POAG.
Results: In the cross-sectional study, the level of E2 was significantly lower in the POAG group than in the normal group ( p < 0.05). Multiple logistic regression showed that the decreased level of E2 was a risk factor of POAG (OR = 0.27, 95% CI = 0.09–0.78, p < 0.05), especially in premenopausal subjects. In the cohort study, there were 29 non-progression subjects and 28 progression subjects. Patients in the progression group had significantly lower levels of E2 than those in the no progression group ( p < 0.01). The decreased level of E2 at baseline was associated with POAG progression (HR = 0.08, 95% CI = 0.02–0.46, p < 0.05), especially in premenopausal subjects. Patients with POAG and with lower baseline E2 levels had significantly lower VF non-progression rates than patients with higher E2 levels (log-rank test p < 0.001), especially premenopausal subjects (log-rank test p < 0.05). Additionally, logistic regression analyses, Cox regression analyses, and Kaplan–Meier survival analysis showed that PROG, LH, FSH, and TESTO were risk factors of POAG and/or significantly associated with POAG progression.
Conclusion: A decreased E2 level is a POAG risk factor and is associated with VF progression in women with POAG, especially in premenopausal subjects. Additionally, other sex hormones (PROG, LH, FSH, and TESTO) might also play a role in POAG pathogenesis.
... Among the risk factors, raised intraocular pressure (IOP) is significant [3]. This disease is a leading cause of blindness world wide [4,5]. Primary open angle glaucoma (POAG), a variant of this disease, in addition to risk factors has also genetic predisposition [6][7][8][9][10]. ...
... На сьогодні лікування глаукоми залишається однією з найбільш невирішених проблем у офтальмології. Незважаючи на появу великої кількості нових фармацевтичних препаратів та різних методів хірургічного лікування, глаукома лідирує серед захворювань, що призводять до погіршення зору, навіть до повної сліпоти [12]. ...
The imaging method in non-penetrating deep sclerectomy (NPDS) was analyzed in 91 patients aged 43 to 89 years with primary open-angle glaucoma. Patients were divided into two groups by age and sex. Group I (n = 46) included the patients who underwent our modified NPDS and group II (n = 45) consisted of patients who were performed the classic NPDS by Fedorov-Kozlov method. After analyzing the data obtained, in group I, staining of juxtacanalicular tissue significantly improved visibility and made it easier to remove compared with group II. The study allows us to conclude about the effectiveness and safety of this visualization technique during surgery.
... Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by progressive optic neuropathy in association with damage of optic nerve head, eventually resulting in the loss of visual function (Kingman, 2004;Sugrue, 1989). The number of people with glaucoma is expected to increase to 111.8 million worldwide by 2040; thus, screening approaches, treatment, and related public health strategies would need to be systematically designed (Tham et al., 2014). ...
Carbonic anhydrase inhibitors (CAIs) are used as systemic and topical agents for lowering intraocular pressure (IOP) in patients with glaucoma. Owing to the wide distribution of CAs and their physiological functions in various tissues, systemic administration of CAIs may lead to unwanted side effects. Thus, exploration of drugs targeting the specific CA isoenzyme in ocular tissues and application of the same as topical eye drops would be desirable. However, the anatomical and physiological barriers of the eyes can limit drug availability at the site. The very low aqueous solubility of CAI agents can further hamper drug bioavailability, consequently resulting in insufficient therapeutic efficacy. Solubilization of drugs using cyclodextrin (CD) complexes can enhance both solubility and permeability of the drugs. The use of CD for such purposes and development and testing of topical CAI eye drops containing CD have been discussed in detail. Further, pharmaceutical nanotechnology platforms were discussed in terms of investigation of their IOP-lowering efficacies. Future prospects in drug discovery and the use of CD nanoparticles and CD-based nanocarriers to develop potential topical CAI formulations have also been described here.
... Glaucoma represents a group of neurodegenerative diseases characterized by optic nerve damage and the slow progressive death of retinal ganglion cells (RGCs). Indeed, glaucoma is regarded as the second cause of irreversible blindness worldwide and it is estimated that its incidence will increase to more than 112 million cases in the future [1][2][3]. ...
Retinal ganglion cells (RGCs) are a population of neurons of the central nervous system (CNS) extending with their soma to the inner retina and with their axons to the optic nerve. Glaucoma represents a group of neurodegenerative diseases where the slow progressive death of RGCs results in a permanent loss of vision. To date, although Intra Ocular Pressure (IOP) is considered the main therapeutic target, the precise mechanisms by which RGCs die in glaucoma have not yet been clarified. In fact, Primary Open Angle Glaucoma (POAG), which is the most common glaucoma form, also occurs without elevated IOP. This present review provides a summary of some pathological conditions, i.e., axonal transport blockade, glutamate excitotoxicity and changes in pro-inflammatory cytokines along the RGC projection, all involved in the glaucoma cascade. Moreover, neuro-protective therapeutic approaches, which aim to improve RGC degeneration, have also been taken into consideration.
... Glaucoma represents a heterogeneous group of chronically progressive neurodegenerative bilateral diseases of the optic nerve, clinically characterized by optical neuropathy, resulting in retinal ganglion cell death, optic nerve head cupping, and associated specific loss of the visual field [1][2][3]. The aetiology of the disease is considered to be multifactorial [4], while the clinical picture can differ, with a substantial risk of associated blindness, especially in adults over the age of 60 [5]. ...
Through the years, the available psychopharmacological treatments have expanded with numerous new drugs. Besides weight gain, gastro-intestinal problems or Parkinson-like symptoms, ocular adverse effects of psychiatric drugs have been reported. These adverse effects are not common, but can be dangerous for the patient. This review summarises the current knowledge on the risk of raised intraocular pressure and glaucoma entailed by psychopharmacological treatment. Also, it provides updated data for clinicians involved in the treatment of patients with glaucoma or glaucoma risk factors. For this purpose, we performed an extensive literature search in the PubMed database using specific terms. Selective serotonin and noradrenaline reuptake inhibitors are the best evidenced as having no association with glaucoma. Antipsychotics, and especially first generation, seem to have no correlation with an increased intraocular pressure and therefore possibly with a risk of glaucoma, although a special attention should be paid when using ziprasidone. Tricyclic antidepressants, benzodiazepines and topiramate should be avoided in patients diagnosed with glaucoma or at risk. Clinicians should be aware of the possible psychotropic drug induced glaucoma and monitor at risk patients closely in order to prevent this condition. Irrespective of the psychopharmacological regimen taken into consideration, the glaucoma patient should be under the strict supervision of the ophthalmologist.
... Glaucoma is an irreversible neuro-degenerative eye disease that is considered one of the main reasons of visual disability in the world [1] . According to the statistics of the World Health Organization(WHO), there are as many as 78 million glaucoma patients in the world in 2020 [2]. ...
Background: Being one of the most serious causes of irreversible blindness, glaucoma has many subtypes and complex symptoms. In clinic, doctors usually need to use a variety of medical images for diagnosis. Optical Coherence Tomography (OCT), Visual Field (VF) , Fundus Photosexams (FP) and Ultrasonic BioMicroscope (UBM) are widely-used and complementary techniques for diagnosing glaucoma.
Methods: At present, the field of intelligent diagnosis of glaucoma is limited by two major problems. One is the small number of data sets, and the other is the low diagnostic accuracy of Single-Modal Modal.
In order to solve the above two problems, we have done the following work. First, we construct DualSY glaucoma multimodal data set. The four most important subtypes of glaucoma are discussed in this article which are Primary Open Angle Glaucoma (POAG), Primary Angle Closure Glaucoma (PACG), Primary Angle Closure Suspect (PACS) and Primary Angle Closure (PAC). Each patient in the DualSY data set contains more than five medical images, as shown in the figure 4.And DualSY are labeled with image-level multi-labels.
Second, We propose a new Multi-Modal classification network for glaucoma, which is a multiclass classification model with various medical images of glaucoma patients and text information as input. The network structure consists of three main branches to deal with patient metadata, domain-based glaucoma features and medical images. Transfer learning method is introduced into this paper due to the small number of medical image data sets. The flowchart is shown in Figure 5.
Result: Our method on glaucoma diagnosis outperforms state-of-the-art methods. A promising average result of overall accuracy (ACC) of 94.7% is obtained. Our data set outperformed most data sets in glaucoma diagnosis with an accuracy of 87.8%.
Conclusions: The results suggest that medical images such as Heidelberg OCT and three-dimensional fundus photos used in this paper can better express the high-level information of glaucoma and our modal greatly improve the accuracy of glaucoma diagnosis. At the same time, this data set has great potential, and we continue to study this data.
... Accordingly, the medical field accounts almost three quarters of all publications. Medical applications of smart contact lenses include the measurement of corneal temperature [104], intraocular pressure (IOP) [105], [106] and glucose levels [69], [107], [108]. Continuously monitoring these health indicators help improve disease diagnosis and treatment. ...
Contact lenses have traditionally been used for vision correction applications. Recent advances in microelectronics and nanofabrication on flexible substrates have now enabled sensors, circuits and other essential components to be integrated on a small contact lens platform. This has opened up the possibility of using contact lenses for a range of human-machine interaction applications including vision assistance, eye tracking, displays and health care. In this article, we systematically review the range of smart contact lens materials, device architectures and components that facilitate this interaction for different applications. In fact, evidence from our systematic review demonstrates that these lenses can be used to display information, detect eye movements, restore vision and detect certain biomarkers in tear fluid. Consequently, whereas previous state-of the-art reviews in contact lenses focused exclusively on biosensing, our systematic review covers a wider range of smart contact lens applications in HMI. Moreover, we present a new method of classifying the literature on smart contact lenses according to their six constituent building blocks, which are the sensing, energy management, driver electronics, communications, substrate and the interfacing modules. Based on recent developments in each of these categories, we speculate the challenges and opportunities of smart contact lenses for human-machine interaction. Moreover, we propose a novel self-powered smart contact lens concept with integrated energy harvesters, sensors and communication modules to enable autonomous operation. Our review is therefore a critical evaluation of current data and is presented with the aim of guiding researchers to new research directions in smart contact lenses.
... It affects approximately 3% of Australians 50 years and older and increases exponentially with age. 1 It is the leading cause of irreversible, preventable blindness in Australia and the world. [2][3][4] There is no cure for glaucoma, but early detection and treatment with medicines to reduce IOP can halt or significantly slow the progression of vison loss and preclude more invasive surgical interventions. Clinical practice guidelines recommend topical eye drops as a first treatment option to prevent damage to the optic nerve by reducing pressure in the eye(s); followed by laser treatment in conjunction with or as an alternative to drops. 2 5 As a chronic condition, glaucoma requires persistent treatment for optimum management. ...
Objective
Medical therapy can halt or significantly slow the progression of glaucoma if medicines are used in accordance with the guidelines. We used dispensing claims for a 10% sample of all Australians dispensed publicly subsidised glaucoma medicines to determine the prevalence and incidence of glaucoma medicine treatment and to examine treatment persistence between July 2012 and June 2019.
Methods
We estimated incidence and prevalence per 10 000 population for Australian financial years (1 July to 30 June). We defined prevalence as at least one dispensing of any glaucoma medicine and incidence as a dispensing of any glaucoma medicine with no previous dispensing during the preceding 12 months. We estimated duration of treatment for a cohort initiating glaucoma medicines and used Kaplan-Meier methods to estimate the proportion of people persisting on treatment at 6, 12, 18 and 36 months after initiation. We stratified analyses by the number of repeats prescribed at initiation, age, sex and medicine class.
Results
Prevalence remained stable over the study period at around 180/10 000 people/year; incidence was also stable around 36/10 000/year. Among 34 900 people initiating glaucoma medicines, 37.0% remained on treatment at 6 months from initiation, 29.8% at 12 months and 19.2% at 36 months. Median duration of treatment was 13.2 months (IQR: 2.5—not reached) for people initiating prostaglandin analogues and less than 3 months for those initiating other medicine classes.
Conclusion
Prevalence and incidence of glaucoma treatment have not changed in Australia over the past decade. Persistence to treatment increased with age but remained poor throughout the study period.
... Fundus screening of patients with diabetes allows timely identification of patients with sight-threatening DR and is important to prevent vision loss [5]. The World Health Organization has identified glaucoma as the second leading cause of blindness globally, with primary open-angle glaucoma (POAG) being the most common type [6]. POAG is a progressive optic neuropathy with characteristic changes in the optic nerve head, and it is often asymptomatic in earlier stages [7]. ...
Background:
Pathophysiological overlaps exist between diabetes and primary open-angle glaucoma (POAG) and presence of diabetes increases risk of POAG. Considering that diabetic retinopathy (DR) is an ocular complication of diabetes, one could speculate that DR as a severity measure may associate with or even predict POAG. Given that POAG is asymptomatic in early stages, an association to DR may prove clinically important and facilitate an earlier diagnosis of POAG.
Objectives:
To investigate if DR is associated with and predictive of POAG.
Method:
We systematically searched 11 literature databases on May 12th, 2021. We screened a total of 1,535 records and found six studies eligible for qualitative and quantitative analysis. Two independent authors reviewed the studies, extracted data, and evaluated risk of bias within individual studies. Studies were reviewed qualitatively, and meta-analyses were made based on the odds ratios (ORs) with 95 % confidence intervals of the association between DR and POAG using the random-effects model. Subgroup analyses were made on the association between subtypes of DR and POAG.
Results:
Six studies (two longitudinal and four cross-sectional) were eligible for review with a total of 255,614 patients with diabetes, of which 20,483 patients had any degree of DR and 5,258 had POAG. All studies were based on patients with type 2 diabetes except one with both type 1 and type 2 patients. Any DR was not associated with POAG (OR 1.17; 95% confidence interval (CI95%): 0.58-2.35; P = 0.65). Further stratification revealed that neither cross-sectional (OR 1.00; CI 95%: 0.56 to 1.81, P = 0.99) nor longitudinal studies (OR 1.47; CI 95%: 0.57 to 3.78, P = 0.43) demonstrated an association between DR and POAG.
Conclusions:
We did not find convincing evidence of an associations between DR and prevalent or incident POAG.
... Glaucoma is an optic neuropathy that leads to the progressive loss of ganglion cells, defects in the visual field and ultimately to blindness if not adequately managed. 1 The prevalence of glaucoma for the population aged 40-80 years is 3.5%, and the burden of glaucoma has been estimated to grow progressively, reaching 111.8 million people affected in 2040 worldwide. 2 Elevated intraocular pressure (IOP) is the major risk factor for glaucoma progression, and IOP prevents visual field deterioration. 3 The treatment goal for glaucoma is lowering IOP to slow down the damage progression rate to maintain vision-related quality of life according to the patient's life expectancy. ...
Objective
To compare the two surgical techniques in terms of efficacy, safety, and postoperative management over 36 months of follow-up.
Methods
This retrospective clinical cohort study compared the outcome of trabeculectomy surgery and Xen gel implant in patients having uncontrolled glaucoma. Patients were recruited using the following inclusion criteria: uncontrolled intraocular pressure (IOP) on maximally tolerated medical therapy, healthy conjunctiva freely mobile in the superior sector, open-angle, glaucomatous visual field damage, full follow upfollow-up of at least 36 months. Thirty-four patients were submitted to trabeculectomy and 34 to Xen gel implant. We set the lower limit at 6mmHg mm Hg and the upper limit ≤12 mm Hg for criteria A, upper limit to ≤15 mm Hg for criteria B and upper limit ≤18 mm Hg for criteria C. Criteria for success have been characterizedcharacterised according to whether or not this has been achieved without (complete success) or with IOP -lowering medications (qualified success).
Results
For all survival curves, trabeculectomy was superior to Xen gel implant. When considering complete success, the log-rank test for criteria A was statistically significant (pp=0.006), marginally significant for criteria B (pp=0.065) and not significant for criteria C (pp=0.23). When qualified success was considered, trabeculectomy was superior to Xen gel for criteria A, B, and C (pp=0.012, pp=0.033 and pp=0.025, respectively). Higher number of post-operative flat chamber and bleb leakage was observed in the trabeculectomy group.
Conclusion
Xen gel implant techniques offer a better safety profile but a lower IOP reduction compared to compared with the gold -standard technique.
... Glaucoma is the leading cause of irreversible blindness worldwide [1][2][3]. Primary open-angle glaucoma (POAG) predominates over primary angle-closure glaucoma (PACG) in most population-based studies: prevalence of POAG is calculated to be 3.54% in those between 40 and 80 years old [4], and prevalence of PACG is approximately 0.92% [2]. ...
Purpose
To evaluate diagnostic capacity for occludable anterior chamber angle detection with anterior segment optical coherence tomography (AS-OCT) and Pentacam.
Methods
Observational cross-sectional study with AS-OCT and Pentacam. AS-OCT measures: angle opening distance from Schwalbe line (SL) perpendicular (AOD-SL-Perp) and vertical to iris (AOD-SL-Vert), and iridotrabecular angle (ITA). Pentacam measures: anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). We analysed Spearman’s correlation with gonioscopic classification. Area under receiver operating characteristic curves (AUCs) for occludable angle detection were compared. Agreement between iridocorneal values of methods was evaluated.
Results
Seventy-four left eyes of 74 patients. Correlation between temporal AS-OCT and gonioscopy: 0.83 (p < 0.0001) AOD-SL-Perp temporal, 0.82 (p < 0.0001) AOD-SL-Vert temporal, and 0.69 (p < 0.0001) ITA temporal. Correlation between AS-OCT nasal and gonioscopy: 0.74 (p < 0.0001) AOD-SL-Perp nasal, 0.74 (p < 0.0001) AOD-SL-Vert nasal, and 0.70 (p < 0.0001) ITA nasal. Correlation of Pentacam with temporal gonioscopy: 0.57 (p < 0.0001) ACD, 0.56 (p < 0.0001) ACV, and 0.63 (p < 0.0001) ACA. Correlation of Pentacam with nasal gonioscopy: 0.47 (IC 0.27–0.73, p < 0.0001) ACD, 0.49 (p < 0.0001) ACV, and 0.56 (CI 0.38–0.7, p < 0.0001) ACA. AS-OCT AUCs: AOD-SL-Perp temporal 0.89 (CI 0.80–0.95), AOD-SL-Vert 0.87 (CI 0.77–0.94), ITA temporal 0.88 (CI 0.78–0.94), AOD-SL-Perp nasal 0.83 (CI 0.72–0.91), AOD-SL-Vert nasal 0.87 (CI 0.77–0.94), and ITA nasal 0.91 (IC 0.81–0.96). Pentacam AUCs: ACD 0.76 (CI 0.64–0.85), ACV 0.75 (CI 0.63–0.84), and ACA 0.84 (CI 0.74–0.92). No statistical differences between different AUCs. Intraclass correlation coefficient (ICC) of ACA (Pentacam) with ITA temporal (AS-OCT) 0.59 and with nasal ITA nasal (AS-OCT) 0.65.
Conclusion
Both systems show high capacity for non-contact occludable angle detection. But agreement between methods is moderate or low.
... Glaucoma is the leading cause of irreversible blindness worldwide. 1 Intraocular pressure (IOP) reduction is the cornerstone of glaucoma management, with medical therapies and laser trabeculoplasties as the main first-line treatment options. When glaucoma progresses despite the best medical treatment, however, surgical treatment may become essential to halt disease progression. ...
Aim and background:
The present case report describes a novel surgical technique combining XEN gel stent implantation and deep sclerectomy: XEN-augmented deep sclerectomy (XEN-DS).
Case description:
An active 96-year-old Caucasian woman suffering from pseudoexfoliative glaucoma (PEXG) presented with intraocular pressure (IOP) of 24 mm Hg and a double arcuate visual field defect [mean deviation (MD) -9.6 dB] in her only functional eye despite maximal medical therapy. Considering (1) the magnitude of IOP reduction sought, (2) the risk of complications associated with trabeculectomies and glaucoma drainage devices, and (3) the risk of missed appointments due to the patient's personal and social circumstances, it was decided to tailor the surgical treatment to this patient's specific characteristics combining two existing surgical techniques. Following conjunctival dissection, a superficial scleral flap was lifted 2 mm more posteriorly than in conventional DS, and a XEN gel stent was implanted ab externo through the anterior wall of the deep sclerectomy, into the anterior chamber. A mitomycin C-soaked autologous space maintainer was used. No peri- or postoperative complications were observed. Following XEN-DS, her IOP stabilized between 5 mm Hg and 8 mm Hg through 6 months, and her visual field MD improved to -1.5 dB.
Discussion:
The present case report is a proof of concept for this novel surgical technique, confirming that XEN-DS has the potential to achieve substantial and persistent IOP reductions in PEXG with a satisfactory safety profile. Clinical studies are warranted to confirm these results.
How to cite this article:
Niegowski LJ, Gillmann K, Baumgartner JM. XEN-Augmented Deep Sclerectomy: Step-by-step Description of a Novel Surgical Technique for the Management of Open-angle Glaucoma. J Curr Glaucoma Pract 2021;15(3):144-148.
... The pathogenesis of HU has been described as involving the continuous accumulation in the eye of inflammatory cytokines produced by ocular-infiltrating HTLV-1-infected T cells, leading to inflammation of the eye (Kamoi and Mochizuki, 2012a). Ocular inflammation often leads to secondary ocular complications, such as secondary glaucoma, a sight-threatening condition associated with damage to the optic nerve, and subsequent loss of visual field due to elevated intraocular pressure (IOP; Kingman, 2004). ...
Human T-cell lymphotropic virus type 1 (HTLV-1) was the first retrovirus identified as the causative agent of human diseases, such as adult T-cell leukemia, HTLV-1-associated myelopathy, and HTLV-1 uveitis (HU). HU is one of the most frequent ocular inflammatory diseases in endemic areas, which has raised considerable public health concerns. Approximately 30% of HU patients develop secondary glaucoma, which is higher than the general uveitis incidence. We therefore investigated the mechanism underlying the high incidence of glaucoma secondary to HU in vitro. After contact with HTLV-1-producing T cells (MT-2), human trabecular meshwork cells (HTMCs) were infected. The infected cells increased in number, and nuclear factor (NF)-κB expression was activated. Contact between MT-2 cells and HTMCs resulted in significantly upregulated production of inflammatory cytokines, such as IL-6, and chemokines, such as CXCL10, CCL2, and CXCL-8. These findings indicate that the mechanism underlying secondary glaucoma in HU may involve proliferation of trabecular meshwork tissue after contact with HTLV-1-infected cells, resulting in decreased aqueous humor outflow. Upregulated production of inflammatory cytokines and chemokines simultaneously disrupts the normal trabecular meshwork function. This mechanism presumably leads to increased intraocular pressure, eventually resulting in secondary glaucoma.
... Open-angle glaucoma (OAG) is a leading cause of global blindness and is projected to impact greater than 100 million people by the year 2040. [1][2][3] Although glaucoma can occur at any level of IOP, elevated IOP is a significant risk factor and strategies targeting the reduction of IOP are the mainstay of treatment. 1 Considerable innovation has occurred over the last decade with respect to treatment with the emergence of new medical and surgical options. ...
Purpose:
This is a 2-part study to investigate the agreement between pneumatonometry and direct pressure transducer intraocular pressure (IOP) measurements in a perfusion organ culture (POC) model where (1) the perfusion fluid column is open to atmospheric pressure, holding IOP constant to permit evaluation of the impact of negative pressure (NP) on IOP measurements, and (2) the perfusion fluid column is a closed system, allowing IOP to vary with NP application.
Methods:
The first part incorporated a fluid column open to atmospheric pressure, maintaining IOP constant to permit evaluation of the effect of applied NP on IOP measurement accuracy. In the second part, the POC column was closed, allowing IOP to vary with NP application and permit evaluation of agreement between pneumatonometry and pressure transducer measurements. In each part, four perfused tissues were used in thirteen paired pre-set IOP (10, 20, 25, 30 mmHg) and NP (0, 5, 10, 15, 20 mmHg) combinations, resulting in a total of 1040 paired measurements (520 per study). The difference in IOP measurements (Δ IOP = Excursion tonometry - pressure transducer) was calculated at each paired configuration.
Results:
During the first part, the mean Δ IOP was -0.7 ± 1.6 mmHg across all measurements. During the second part, the mean Δ IOP across all measurements was +0.7 ± 1.4 mmHg. At NP settings of -5, -10, -15, and -20 mmHg, across all pre-set IOPs, the mean IOP reduction via Excursion tonometry was 3.1 ± 0.3, 5.6 ± 1.3, 8.5 ± 1.7 and 11.2 ± 1.8 mmHg, respectively.
Conclusion:
Measurement of IOP via Excursion tonometry yields results within the accuracy range of the pneumatonometry device (per manufacturer) and is minimally impacted by NP application. The IOP-lowering results are consistent with previous studies and further support the effectiveness of the Multi-Pressure Dial in lowering IOP relative to atmospheric pressure.
... (9) Globally, glaucoma is the second-leading cause of blindness after cataracts. (10,11) One study has shown that incidence of both POAG and PACG are more in urban than rural area. (12) Although the glaucoma can be traced back in history its identification has been made easy after ophthalmoscope came into being. ...
Introduction: Primary Open Angle Glaucoma causes damage to the fibers of optic nerve which results in permanent visual loss. There may not be any symptoms; this is dangerous because patient may become blind silently. Glaucoma caused by angle closure mechanism causes symptoms and patient seeks medical attendance early. Aims and Objectives: To study clinical types and Factors associated with the Glaucoma patients. Methodology: This was cross-sectional study of the patients reporting to ophthalmology outpatient department or admitted in the ophthalmology wards having symptoms suggestive of Glaucoma, at tertiary health care center during the year 2016. The patients underwent detailed elucidation of history and examination. All essential investigations were undertaken. Attention was also paid to monitor treatment response and follow up. As per above criteria total 64 patients were included into the study. Result: Majority of the Glaucoma patients were from older age group. As age increases the problem of Glaucoma was more prevalent. It was more frequent in Males. More patients had Open angle Glaucoma than close angle or narrow angle. The most common associated factors with Glaucoma patients were Diabetes followed by Systemic Hypertension; Phacomorphic; post Iridocyclitis; Steroid induced Glaucoma; Traumatic Glaucoma. Conclusion: The problem of Glaucoma was more common in Older age and in males. The most common associated factors with Glaucoma patients were Diabetes followed by Systemic Hypertension; Phacomorphic; post Iridocyclitis; Steroid induced Glaucoma; Traumatic Glaucoma. So these factors should be considered during diagnosis and management of Glaucoma patients.
... Glaucoma is the leading cause of irreversible blindness affecting 3-5% of the worldwide population over 40 years old. 1,2 The most recent estimate of bilateral glaucoma blindness from 2020 is 5.9 million people. 3 The number affected is expected to continue to grow to a projected more than 111 million people by 2040 disproportionately in Africa, which has the highest primary open angle glaucoma (POAG) prevalence, and Asia, which has the highest primary acute angle glaucoma prevalence. ...
Daniel Laroche,1,2 Melanie Scheive3 1Department of Ophthalmology, New York Eye and Ear Infirmary, Icahn School of Medicine of Mount Sinai, New York, NY, USA; 2Advanced Eyecare of New York, New York, NY, USA; 3Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USACorrespondence: Daniel Laroche, Department of Ophthalmology, New York Eye and Ear Infirmary and Advanced Eyecare of New York, 49 West 127th Street, New York, NY, 10027, USA, Tel +1 212663-0473, Email dlarochemd@aol.comAbstract: Glaucoma continues to be a leading cause of blindness worldwide for the same reasons as in the past several decades, including the lack of early detection, improper treatment, and non-adherence to therapy. Medical therapy continues to be the first-line therapy even as surgical techniques are improving in their safety and efficacy. To turn the tide in preventing blindness from glaucoma, attention must be focused on targeted patient education, screening, effective treatment, and addressing health disparities. To achieve this, early safer cataract surgery and microinvasive glaucoma surgery must be considered as a first-line therapy in addition to medical therapy to best lower both intraocular pressure and the medication burden.Keywords: glaucoma, prevention, cataract surgery, lensectomy, MIGS
to assess the features of the retinal nerve fiber layer (RNFL), ganglion complex (GC) and the microcirculatory bed of the retina in patients with primary open-angle glaucoma (POAG) using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Materials and methods: The study involved 20 people (11 females, 9 males). Patients were divided into 2 groups. The first group included 10 clinically healthy individuals, the second group - 10 patients with POAG. All patients underwent standard ophthalmic examination, OCT / OCTA examination of the RNFL, GC and retinal microcirculatory bed. Results: The study identified the most sensitive indicators to the progression of the glaucoma process. It was found that the RNFL thickness and the density of the retinal vascular progressively decrease with the development of glaucoma opticopathy. Compared with the group of healthy individuals in patients with POAG, the RNFL thickness in the lower temporal sector of the peripapillary zone was reduced by 44.04% (p <0,01). Compared with healthy individuals, the density of the superficial vascular plexus decreased by 16.3%, deep - by 12.5% (p <0,01). The perimeter of the foveolar avascular zone in patients with glaucoma increased by 31.01%, the area of the foveolar avascular zone increased 1.6 times (p <0.01). Conclusions: OCT and OCTA are effective methods for assessing the state of GC, RNFL and microcirculatory bed of the retina, which allow for non-invasive monitoring and evaluation of these indicators in patients with POAG.
Introduction: Cyclodestructive procedures involve destroying part of the ciliary epithelium to reduce production of aqueous humor and lower intraocular pressure (IOP). Due to its complication rate, cycloablation was historically reserved for eyes with refractory glaucoma that have failed previous filtration procedures, have poor vision and IOP control despite maximal medical therapy, and for relief of pain in blind eyes.
Areas Covered: In this review paper, we cover different forms of transscleral cyclophotocoagulation (TCPC), their degrees of success, and their complication rates. Contact diode laser transscleral cyclophotocoagulation is currently a commonly used method. Micropulse diode laser transscleral cyclophotocoagulation is a newer paradigm that has shown promising results. We also review the outcomes of TCPC in eyes with different subtypes of glaucoma and ocular history. As the modalities improve, TCPC may be safer than previously assumed and the indications for TCPC may be expanded.
Expert Opinion: In general, TCPC is an effective and relatively safe way to treat patients with glaucoma. More comparative studies are required to determine if TCPC should be used at earlier stages of disease.
Automated glaucoma detection using deep learning may increase the diagnostic rate of glaucoma to prevent blindness, but generalizable models are currently unavailable despite the use of huge training datasets. This study aims to evaluate the performance of a convolutional neural network (CNN) classifier trained with a limited number of high-quality fundus images in detecting glaucoma and methods to improve its performance across different datasets. A CNN classifier was constructed using EfficientNet B3 and 944 images collected from one medical center (core model) and externally validated using three datasets. The performance of the core model was compared with (1) the integrated model constructed by using all training images from the four datasets and (2) the dataset-specific model built by fine-tuning the core model with training images from the external datasets. The diagnostic accuracy of the core model was 95.62% but dropped to ranges of 52.5–80.0% on the external datasets. Dataset-specific models exhibited superior diagnostic performance on the external datasets compared to other models, with a diagnostic accuracy of 87.50–92.5%. The findings suggest that dataset-specific tuning of the core CNN classifier effectively improves its applicability across different datasets when increasing training images fails to achieve generalization.
Objectives
Geriatric patients can be non-adherent to ophthalmic glaucoma medications because of complex eye drops instillation techniques and forgetfulness, so pharmacists can play their part in improving the clinical outcomes of patients by acting as care providers. The purpose of the current study was to implement various pharmacist-led interventions to improve adherence to glaucoma medications and to evaluate the outcomes of interventions in the geriatric population.
Methods
The Morisky Green Levine (MGL) adherence scale was used for analysis because it measures the extent of non-adherence and analyses the reasons for it. The interview-based sessions were conducted with control and interventional groups followed by educational interventions, including techniques for eye drop instillation, graphical images, precautionary measures, and individual patient counselling for the interventional group. Patients were asked to complete the adherence scale after the conclusion of every follow-up session for a duration of 6 months.
Results
After 6 months of pharmacist-led interventions, a significant shift was found in the interventional group from low to high adherence according to MGL scale evaluation. Moreover, the number of patients in the interventional group whose intraocular pressure was in the safe range significantly increased and follow-up sessions significantly improved the patient’s knowledge about glaucoma.
Conclusion
The results of this pharmacist-led educational interventional study showed it was effective in improving adherence to glaucoma medications in the geriatric patients, who showed better adherence scores and improved intraocular pressure.
This unicentric randomized clinical trial was designed to compare the surgical outcomes of mitomycin C-enhanced trabeculectomy (MMC-TRAB) with and without subtenon triamcinolone acetonide (TAAC) injection in patients with non-inflammatory glaucomas. This trial is registered at the Brazilian Registry of Clinical Trials (ReBEC) under the register number RBR-53f8nh. Consecutive non-inflammatory glaucoma patients requiring surgical intervention were randomized into two groups. In the control group, eyes underwent standard MMC-TRAB, while in the intervention group, besides the standard MMC-TRAB, these eyes also received a subtenon TAAC injection (4mg) close to the bleb site at the end of the surgery. The main outcomes of the study were surgical success rates, intraocular pressure (IOP) and number of medications at all timepoints. Success was defined as IOP ≤ 15 mmHg and subdivided in complete or qualified according to the need of medication. A total of 75 eyes of 63 different patients were included (intervention group = 39 eyes; control group = 36 eyes). There was no difference between groups at baseline (p>0.11). Multivariable regression analysis indicated that IOP levels were significantly lower in the intervention group at 18 and 24 months of follow-up when number of medications was considered as a covariate (P
La connaissance de la dynamique artérielle ophtalmique est pauvre, principalement issue des études Doppler et rien n'existe sur la composante veineuse. La physiopathologie du Glaucome est encore débattue et perfectible. Les études pointent notamment la vascularisation comme origine potentielle de cette affection, sans parvenir à proposer un modèle physiopathologique qui rassemble les différentes hypothèses. L'IRM en contraste de phase (IRM-PC) est une séquence non invasive, quantitative pour la mesure de la dynamique vasculaire. Principalement utilisée sur les artères de larges diamètres l'IRM PC, n'est à ce jour, pas utilisée sur l'artère et la veine ophtalmique. Le but de ce travail est de quantifier par IRM PC la dynamique vasculaire de l'artère ophtalmique (AO) et de la veine ophtalmique supérieure (VOS) sur une population saine. Dans une seconde étape d'appliquer l'IRM PC chez des patients atteints de glaucome. 21 volontaires sans affections ophtalmiques et 11 patients diagnostiqués comme porteurs d'un Glaucome ont été inclus. Les sujets ont bénéficié dans les mêmes conditions d'un examen sur une IRM 3 Tesla disposant d'une séquence IRM PC. Les AO et VOS gauches et droites ont été identifiées sur des séquences morphologiques pour positionner perpendiculairement l'IRM PC. Les IRM PC ont été analysées par un logiciel dédié pour calculer le débit a chaque phase du cycle cardiaque et construire la courbe d'évolution du débit au cours du cycle cardiaque de chaque vaisseau. Et en calculer : le débit moyen, maximal et minimal et les vitesses. Les résultats obtenus comme référence physiologique, montrent la faisabilité de cette technique. Il est mis en évidence l'existence d'une pulsatilité veineuse non négligeable au cours du cycle cardiaque. La dynamique vasculaire des patients glaucome (pulsatilité) était diminuée. Une corrélation largement significative entre le débit et la vitesse maximale a été mise en évidence dans la veine ophtalmique supérieure des témoins, qui n'était pas retrouvée chez les patients. En conclusion, notre travail a confirmé la possibilité d'étudier par IRM-PC la dynamique du débit sanguin dans l'AO et la VOS. Dans le glaucome, nous avons montré l'existence d'une modification significative de la dynamique vasculaire de la VOS pouvant résulter d'une altération de l'écoulement du réseau capillaire et/ou de la pression d'aval
Glaucoma is the leading cause of irreversible blindness, affecting around 80 million people worldwide. Glaucoma is a multifactorial disease of poorly understood pathogenesis, with intraocular pressure being the most significant risk factor. Currently there are different methods of intraocular pressure measurement, based on different physical principles, some of which are continuous measurement methods and others which are only measured in the medical office. The importance of the corneal biomechanical properties in intraocular pressure measurement is becoming increasingly clear. With the development of new instruments that can measure them, it will become possible to obtain more accurate intraocular pressure measurements within a short period of time. In the future, glaucoma patients will be better monitored with instruments capable of measuring intraocular pressure 24 hours a day.
Prolonged drug efficacy to reduce the number of administrations is a key factor in the successful treatment of glaucoma through topical drug delivery to the eye. Therefore, we propose a new strategy for iontophoretic ocular delivery of drug-loaded nanoparticles. Considering safety and convenience, our strategy is involved with topical administration of the drug-loaded nanoparticles followed by their permeation into the eye tissues via noninvasive iontophoresis, using the skin-attached electrodes. Thus, those nanoparticles stayed longer in the eye, and during this period, the drug was released in a sustained manner, thereby prolonging drug exposure even with one-time treatment. The nanoparticles were made of poly(lactic-co-glycolic acid) (PLGA), which were loaded with a glaucoma drug, latanoprost. We varied the size of the nanoparticles at 100, 200, 300, and 500 nm and sought to find the optimum size under the fixed conditions for iontophoresis proposed in this work (4 mA; 30 min). Even with iontophoresis through the skin-attached electrodes, the nanoparticles were indeed deposited in the eye tissues, where with an increase in particle size, drug release was more sustained, but fewer particles could permeate into the eye tissues. Because of these two competing factors, iontophoretic delivery of the 300-nm particles exhibited the most prolonged drug efficacy in vivo for more than 7 days, and showed an approximately 23-fold increase in drug efficacy compared with that of Xalatan®, a commercially available eye drop of latanoprost developed for once-a-day administration every day.
Statement of Significance
To treat glaucoma, conventional eye drops are often prescribed; however, they often require multiple daily administrations due to rapid preocular clearance. To resolve this, we suggest a noninvasive iontophoretic ocular delivery of latanoprost-loaded PLGA nanoparticles using the skin-attached electrodes. Even with iontophoresis via the skin-attached electrodes, the nanoparticles can indeed be deposited into the eye tissues. However, with an increase in particle size, fewer particles can permeate into the eye tissues, although drug release is more sustained. Therefore, the particles with a size of 300 nm show the optimal in vivo delivery profile in this work, where the drug efficacy can be extended for more than 7 days with a single administration.
Pseudoexfoliation (PXF) syndrome is an important public health concern requiring individual population level analysis. Disease prevalence differs by geographic location and ethnicity, and has environmental, demographic, genetic, and molecular risk factors have been demonstrated. Epidemiological factors that have been associated with PXF include age, sex, environmental factors, and diet. Genetic and molecular components have also been identified that are associated with PXF. Underserved populations are often understudied within scientific research, including research about eye disease such as PXF, contributing to the persistence of health disparities within these populations. In each population, PXF needs may be different, and by having research that identifies individual population needs about PXF, the resources in that population can be more efficiently utilized. Otherwise, PXF intervention and care management based only on the broadest level of understanding may continue to exacerbate health disparities in populations disproportionally burdened by PXF.
Increasing the level of cyclic adenosine 3, 5'-monophosphate is an important mechanism for axon outgrowth and recovery of central nervous system function. This study aimed to investigate the effects of papaverine, a non-specific phosphodiesterase inhibitor, on axon outgrowth of primary retinal ganglion cells from Sprague Dawley rats. Experiments were performed on primary retinal ganglion cells extracted from Sprague Dawley rat pups within 48-72 h of birth. At 24 h after seeding, immunofluorescence was used to identify and calculate the purity of retinal ganglion cells isolated by an improved two-step immunopanning method developed by author Sujia Ma. The effects of a range of papaverine concentrations on axon outgrowth of primary retinal ganglion cells cultures were observed by immunofluorescence and measured by ImageJ software at three different time points: 24, 48, and 72 h. The ability of papaverine to enable retinal ganglion cells to overcome the inhibitory effects of glial scar component chondroitin sulfate proteoglycans was examined using chondroitin sulfate proteoglycans-coated culture plates. Rp-adenosine 3',5'-cyclic monophosphorothioate triethylammonium salt, a blocking agent of cyclic adenosine 3, 5'-monophosphate, and dibutyryl cyclic adenosine 3, 5'-monophosphate, an analogue of cyclic adenosine 3, 5'-monophosphate, were used to explore the mechanism of papaverine in promoting retinal ganglion cells axon outgrowth. Our study shows 2 μg/mL papaverine concentration significantly promoted axon outgrowth in primary retinal ganglion cells and restored axon outgrowth of these cells on chondroitin sulfate proteoglycans. Axon outgrowth was blocked by Rp-adenosine 3',5'-cyclic monophosphorothioate triethylammonium salt and obviously promoted by dibutyryl cyclic adenosine 3, 5'-monophosphate. Our study is the first to describe the use of papaverine to promote axon outgrowth of retinal ganglion cells. These results may help to expand the application of papaverine, and they provide a cytological basis for papaverine in the treatment of optic nerve injury caused by glaucoma and other diseases.
The Continuous-Time Hidden Markov Model (CT-HMM) is an attractive approach to modeling disease progression due to its ability to describe noisy observations arriving irregularly in time. However, the lack of an efficient parameter learning algorithm for CT-HMM restricts its use to very small models or requires unrealistic constraints on the state transitions. In this paper, we present the first complete characterization of efficient EM-based learning methods for CT-HMM models, as well as the first solution to decoding the optimal state transition sequence and the corresponding state dwelling time. We show that EM-based learning consists of two challenges: the estimation of posterior state probabilities and the computation of end-state conditioned statistics. We solve the first challenge by reformulating the estimation problem as an equivalent discrete time-inhomogeneous hidden Markov model. The second challenge is addressed by adapting three distinct approaches from the continuous time Markov chain (CTMC) literature to the CT-HMM domain. Additionally, we further improve the efficiency of the most efficient method by a factor of the number of states. Then, for decoding, we incorporate a state-of-the-art method from the (CTMC) literature, and extend the end-state conditioned optimal state sequence decoding to the CT-HMM case with the computation of the expected state dwelling time. We demonstrate the use of CT-HMMs with more than 100 states to visualize and predict disease progression using a glaucoma dataset and an Alzheimer's disease dataset, and to decode and visualize the most probable state transition trajectory for individuals on the glaucoma dataset, which helps to identify progressing phenotypes in a comprehensive way. Finally, we apply the CT-HMM modeling and decoding strategy to investigate the progression of language acquisition and development.
Ziel dieser Arbeit war es ein Quantifizierungstool zu erstellen, welches in seiner Konfiguration möglichst breit angepasst werden kann und dieses auf seine Reproduzierbarkeit und Verlässlichkeit zu testen.
Glaucoma, a progressive optic neuropathy characterized by retinal ganglion cell degeneration and visual field loss, is the leading cause of irreversible blindness worldwide. Intraocular pressure (IOP) is presently the only modifiable risk factor demonstrated to slow or halt disease progression; however, glaucomatous damage persists in almost 50% of patients despite significant IOP reduction. Many studies have investigated the non-IOP-related risk factors that contribute to glaucoma progression as well as interventions that can prevent or delay glaucomatous neurodegeneration and preserve vision throughout life, independently of IOP. A vast number of experimental studies have reported effective neuroprotection in glaucoma, and clinical studies are ongoing attempting to provide strong evidence of effectiveness of these interventions. In this review, we look into the current understanding of the pathophysiology of glaucoma and explore the recent advances in non‐IOP related strategies for neuroprotection and neuroregeneration in glaucoma.
Glaucoma and dry eye are two of the most frequently occurring ocular problems presenting ophthalmology patients but are not often addressed as part of a cohesive therapy plan. Presented are the current thinking behind optimizing the ocular surface in patients who also have a need for ongoing glaucoma therapy. This involves a multipronged approach to effectively identifying dry eye, using appropriate dry eye therapeutics, as well as targeting glaucoma treatments that are tolerable in this group of patients. This may include minimizing glaucoma drops that have preservatives, using laser treatment for glaucoma earlier in the disease course, and utilizing glaucoma surgery to lower intraocular pressure with fewer topical medications.
This prospective study aims to evaluate the correlation between myopic severity and normal tension glaucoma (NTG) by investigating IOP changes following water-drinking test (WDT). We reviewed 61 patients with NTG during an interval of three years, of which 31 were highly myopic (HM) and 30 were non-highly myopic (NHM). Basic characteristics such as age, gender, spherical equivalence, baseline IOP, visual field parameters, and average retinal nerve fiber layer thickness were compared between NTG patients with and without high myopia. The IOP parameters obtained following WDT were then compared between the HM and NHM NTG groups. Intragroup analysis revealed significant IOP elevation following WDT within the 45-minute duration in both groups. However, no significant differences in IOP parameters were observed between the HM and NHM NTG groups. In conclusion, although the pattern of IOP fluctuations was different, the extent of IOP fluctuations and peak IOP following WDT was similar between the HM and NHM NTG groups, suggesting that myopic severity probably has a limited role in NTG. Lastly, WDT was an effective tool for eliciting IOP peaks when 24-hour IOP monitoring is not available.
This paper addresses the applicability of a novel neural network model on early detection of Glaucoma disease. In this work, we propose to incorporate a especial case of Random Vector Functional Link (RVFL) into Rough neural architectures that consist of random weights rough (RW-Rough) neurons to handle the existing uncertainty in medical datasets. Moreover, for accurate and efficient parameter selection, a combination of the Biased Random Key Genetic Algorithm and random-weights neural networks is proposed for the model’s training. To evaluate the proposed method, the medical records of 500 normal and 400 glaucomatous persons have been collected from Labbafinezhad medical center, Tehran, Iran. Experimental results on the collected dataset show the superiority of the proposed model in comparison with recent data-driven algorithms in terms of sensitivity, specificity, and accuracy.
To investigate the effects of oral nimodipine on ocular haemodynamic parameters and colour contrast sensitivity in patients with normal tension glaucoma (NTG).
The study was performed in a randomised, placebo controlled, double masked, crossover design.
Nimodipine (60 mg) or placebo was administered to 14 consecutive NTG patients.
The effects or oral nimodipine or placebo on ocular and systemic haemodynamic parameters and colour contrast sensitivity along the tritan axis were studied two hours after administration. Optic nerve head blood flow (ONHBF) and choroidal blood flow (CHBF) were assessed with laser Doppler flowmetry. Ocular fundus pulsation amplitude (FPA) was measured with laser interferometry. Colour contrast sensitivity (CCS) was determined along the tritan colour axis.
ONHBF, CHBF, FPA, intraocular pressure and CCS were assessed in patients with NTG.
Mean ocular FPA increased by 14% (SD 14%) (p = 0.0008), ONHBF by 18% (SD 16%) (p = 0.0031), and CHBF by 12% (SD 14%) (p<0.001) after administration of nimodipine. Nimodipine also decreased the threshold of colour contrast sensitivity along the tritan colour axis (-14% (SD 12%); p = 0.048). However, individual changes in FPA, ONHBF, or CHBF were not correlated with changes in threshold of CCS along the tritan colour axis.
The results indicate that nimodipine increases ONH and choroidal blood flow in NTG patients and improves CCS. The latter effect does not, however, seem to be a direct consequence of the blood flow improvement.
Four glaucoma patients with rapid progression of visual field damage and excavation of the optic nerve head despite normal or well-controlled intraocular pressure had one factor in common: low systemic blood pressure. Furthermore, when monitored during 24 h, a sustained blood pressure drop during sleep was always observed. Systemic hypotension, therefore, might be a significant risk factor for glaucomatous damage. The authors recommend measuring the blood pressure frequently in such patients, especially at night.
Four patients with glaucoma-like discs, normal visual fields, and normal ocular pressures (less than 21 mmHg), first detected by direct ophthalmoscopy, were followed without treatment. Increased ocular pressures (greater than or equal to 21 mmHg) subsequently developed in these patients at an average of 8.1 years after the recognition of their glaucoma-like discs. Before the increased ocular pressure developed, two patients showed retinal nerve fiber layer loss and one showed optic disc hemorrhages. There are two possible hypotheses to explain this sequence of events. The first is that the optic discs and nerve fiber layer defects were produced by abnormal diurnal levels of ocular pressures or levels of ocular pressure, although less than 21 mmHg, which may be abnormal for the optic disc. The second hypothesis is that there are two independent events, one producing abnormalities in the optic disc and nerve fiber layer and a second producing the increased ocular pressure.
We assessed microcirculation in nailfold capillaries of 22 patients with classical migraine and 22 normal subjects matched for age and sex using video-microscopy. Blood flow measurements were performed under standardized room temperature, after a 3-min warm water bath and after local cooling. Under standardized conditions, skin temperature at the fingertip was significantly lower in patients with migraine. Morphological differences, however, could not be found between patients and controls. After cooling of the nailfold area, blood flow stop due to vasospasm occurred in 18 of the 22 migraine patients in contrast to 1 of the 22 control subjects only. Capillary blood cell velocity was significantly decreased in the migraine group under all test conditions. Drug treatment did not account for the different prevalences of vasospasm in migraine patients and normal controls. Our findings demonstrate that patients with migraine often have subclinical microcirculatory disorders of the upper limbs.
In order to estimate the prevalence rate of Raynaud's phenomenon in the Japanese population, 1875 males and 1998 females were interviewed by medical doctors, aided by a typical photograph of Raynaud's phenomenon. The prevalence rates were 3.3% in males and 2.5% in females. Approximately 60% of the male cases of Raynaud's phenomenon were presumed to be caused by vibration syndrome or trauma to the fingers. Prevalence rates excluding these two causes were 1.2% in males and 2.2% in females. The male:female ratio of these prevalence rates was 1:1.9. The prevalence rate for males increased with age, while that for females tended to decrease. The male:female ratio for subjects under 50 years old was 1:5.2 and for those 50 years old or older the ratio was 1:1.1. The prevalence rates of symptoms limited to finger whitening, excluding cases caused by vibration syndrome or trauma, were 1.0% in males and 1.8% in females. Both of these prevalence rates were lower than those of male and female Caucasians.
To evaluate blood-flow parameters in three different groups of patients with primary open-angle glaucoma.
Hemodynamic parameters in the ophthalmic artery, central retinal artery, central retinal vein, and lateral and medial short posterior ciliary arteries were evaluated by color Doppler imaging in 237 patients with primary open-angle glaucoma and 124 age-matched normal control subjects. Group A consisted of 56 patients with primary open-angle glaucoma with treated intraocular pressure higher than 20 mm Hg; group B, of 103 patients with primary open-angle glaucoma with progression of glaucomatous damage despite intraocular pressure of 21 mm Hg or less; and group C, of 78 patients with normal-tension glaucoma.
All patients showed a significant decrease in end-diastolic velocities (P < .01) and a significant increase in resistivity index (P < .05) in all arteries measured. Peak-systolic velocities were normal in the ophthalmic artery in all three groups. In the central retinal artery and the short posterior ciliary arteries, however, patients in groups B and C had significantly reduced peak-systolic velocity (P < .05) compared with normal control subjects. Peak-systolic velocity in group A did not differ significantly from that of normal control subjects. Maximal and minimal blood-flow velocities in the central retinal vein were significantly lower in groups B and C (P < .001) compared with normal control subjects. In group A, only minimal blood-flow velocity was significantly reduced (P < .05).
Hemodynamic parameters in the extraocular vessels are altered in patients with glaucoma. Reduced blood-flow velocities may be secondary as well as contributory to glaucomatous damage.
Both intraocular pressure (IOP) and vascular factors appear to play an important role in the pathogenesis of glaucomatous optic neuropathy (GON). Arteriosclerosis and its risk factors are of minor importance, whereas vasospastic syndrome clearly is associated with GON. A vascular endotheliopathy seems to be involved in the diathetic hyperresponsiveness to stimuli, such as coldness or emotional stress. This in turn leads to a compromised autoregulation, and thereby renders the eye more sensitive to IOP or to a decrease in blood pressure. A variation in ocular perfusion may lead to an increase in free oxygen radicals. This may finally lead to apoptosis.
To evaluate the effect of Ginkgo biloba extract (GBE) on preexisting visual field damage in patients with normal tension glaucoma (NTG).
Prospective, randomized, placebo-controlled, double-masked cross-over trial.
Twenty-seven patients with bilateral visual field damage resulting from NTG.
Patients received 40 mg GBE, administered orally, three times daily for 4 weeks, followed by a wash-out period of 8 weeks, then 4 weeks of placebo treatment (identical capsules filled with 40 mg fructose). Other patients underwent the same regimen, but took the placebo first and the GBE last. Visual field tests, performed at baseline and at the end of each phase of the study, were evaluated for changes.
Change in visual field and any ocular or systemic complications.
After GBE treatment, a significant improvement in visual fields indices was recorded: mean deviation (MD) at baseline versus MD after GBE treatment, 11.40 +/- 3.27 dB versus 8.78 +/- 2.56 dB (t = 8.86, P = 0.0001, chi-square test); corrected pattern standard deviation (CPSD) at baseline versus CPSD after GBE treatment, 10.93 +/- 2.12 dB versus 8.13 +/- 2.12 dB (t = 9.89, P = 0.0001, chi-square test). No significant changes were found in intraocular pressure, blood pressure, or heart rate after placebo or GBE treatment. Any ocular and systemic side effects were recorded for the duration of the trial.
Ginkgo biloba extract administration appears to improve preexisting visual field damage in some patients with NTG.
Several studies indicate that calcium channel blockers improve the clinical course of normal tension glaucoma (NTG), whereas the underlying mechanism is not fully investigated. Hemodynamic improvement and neuroprotective effects are discussed. In this study, we measured the hemodynamic effects of nimodipine on retinal circulation.
Sixteen patients with NTG and clinical signs of vasospastic hyperreactivity, such as suffering from extremely cold hands and feet, were consecutively selected out of the local glaucoma registry. Ten healthy age-matched volunteers were included as controls. Retinal capillary blood flow was measured by Scanning Laser Doppler Flowmetry in both eyes before and 90 +/- 10 minutes after a single oral dose of 30 mg nimodipine.
Before administration of nimodipine, retinal capillary blood flow was significantly reduced in NTG patients compared with controls (262 +/- 80 vs. 487 +/- 164 AU, P < 0.001). Nimodipine increased retinal capillary blood flow in NTG patients by 91 +/- 73% (P < 0.001) to values of healthy controls (440 +/- 113 vs. 439 +/- 123 AU, P = 0.635). In controls, nimodipine did not show significant effects.
In NTG patients with additional vasospastic symptoms, retinal capillary blood is significantly reduced in comparison with healthy controls. Single-dose nimodipine yields to a normalization of retinal circulation in NTG patients up to values of healthy controls 90 minutes after drug administration.
To investigate the progression of visual field loss and to explore the prognosis of glaucomatous optic neuropathy in patients with chronic angle-closure glaucoma (CACG) after their intraocular pressures were well controlled under 21 mmHg.
Forty-seven eyes of 29 patients in the Department of Ophthalmology in PUMC Hospital were included. All the patients had at least two separate tests of visual fields using the 24-2 program of the Humphery Visual Field Analyzer after their intraocular pressure were well controlled under 21 mmHg after sugery. The visual fields of patients were followed routinely for at least 1 year. In addition, all patients were divided into 2 groups according to follow-up period: 1-2 years group and over 2 years group. Visual field scores were calculated with the Advanced Glaucoma Intervention Study (AGIS) method. The visual fields were divided 5 sections and the sensitivity and defect depth of each section were calculated.
No statistically significant differences were found in terms of AGIS scores, localized sensitivities and localized defects within the time interval of the observation.
Glaucomatous optic neuropathy is not likely to progressively deteriorate in CACG cases once their intraocular pressure are well controlled under 21 mmHg.
To compare thirst, drinking behaviour, and endothelin-1 (ET-1) plasma levels between vasospastic and non-vasospastic subjects.
We compared 67 subjects with a primary vasospastic syndrome with 64 age- and sex-matched non-vasospastic control subjects. A detailed medical history was recorded, including a questionnaire containing queries about thirst and drinking behaviour, history of migraine or unspecific headache, history of episodes of low blood pressure, and smoking habits. Body mass index (BMI) was calculated and blood samples were drawn for ET-1 measurements.
Subjects with a vasospastic syndrome reported a reduced desire to drink and a lower estimated quantity of daily fluid intake, more often forgot to drink, more often had both migraine and unspecific headache, more often had episodes of low blood pressure, and had an increased plasma level of ET-1. These features differed statistically significantly between the two groups. There was also a non-significant trend among vasospastic subjects to smoke less and to have a smaller BMI.
A reduced desire to drink is found frequently among vasospastic subjects.
Elevated intraocular pressure (IOP), a well-known risk factor for glaucoma, has recently been shown to be associated with some metabolic complications and obesity. We investigated the link between IOP and metabolic disturbances, focusing especially on metabolic syndrome and insulin resistance.
Eye examinations, including IOP measurement, were conducted on 943 subjects (533 men and 410 women). Body mass index (BMI), percent body fat, waist circumference, systolic and diastolic pressure, fasting insulin, glucose, lipids, and other metabolic parameters were measured. The homeostasis model assessment (HOMA) score and McAuley index were calculated to assess whole-body insulin resistance.
Both of these insulin resistance indices showed positive associations with IOP (p < 0.05), even after statistical adjustment for other risk factors. IOP was higher in participants with metabolic syndrome, as compared to those who did not have metabolic syndrome. The mean IOP tended to increase linearly with the presence of increasing numbers of components for metabolic syndrome.
These results suggest that insulin resistance might contribute to an explanation that would account for many previous findings concerning the association between IOP and obesity, hypertension, and diabetes.